Project description:Fatty acid-binding protein 4 (FABP4) plays an essential role in metabolism and inflammatory. However, the role of FABP4 in alcoholic steatohepatitis (ASH) remains unclear. This study aimed to investigate the function of FABP4 and the underlying mechanisms in the progression of ASH.
Project description:The mechanisms underlying the progression of non-alcoholic steatohepatitis (NASH) are not completely elucidated. In this study we have integrated gene expression profiling of liver biopsies of NASH patients with translational studies in a mouse model of steatohepatitis and with pharmacological interventions in isolated hepatocytes to identify a novel mechanism implicated in the pathogenesis of NASH. By using high-density oligonucleotide microarray analysis we identified a significant enrichment of known genes involved in the multi-step catalysis of long chain polyunsaturated fatty acids, including delta-5 and 6 desaturases. A combined inhibitor of delta-5 and delta-6 desaturases significantly reduced intracellular lipid accumulation and inflammatory gene expression in isolated hepatocytes. Gas chromatography analysis revealed impaired delta-5 desaturase activity toward the omega-3 pathway in livers from mice with high-fat diet (HFD)-induced NASH. Consistently, restoration of omega-3 index in transgenic fat-1 mice expressing an omega-3 desaturase, which allows the endogenous conversion of omega-6 into omega-3 fatty acids, produced a significant reduction in hepatic insulin resistance, hepatic steatosis, macrophage infiltration and necroinflammatory liver injury, accompanied by attenuated expression of genes involved in inflammation, fatty acid uptake and lipogenesis. These results were comparable to those obtained in a group of mice receiving a HFD supplemented with EPA/DHA. Of interest, hepatocytes from fat-1 mice or supplemented with EPA exhibited synergistic anti-steatotic and anti-inflammatory actions with the delta-5/ delta-6 inhibitor. Conclusion: These findings indicate that both endogenous and exogenous restoration of the hepatic balance between omega-6 and omega-3 fatty acids and/or modulation of desaturase activities exert preventive actions in NASH. The complete database comprised the expression measurements of 18185 genes for liver sample groups: 8 non-alcoholic steatohepatitis (NASH ) and 7 control samples. This dataset is part of the TransQST collection.
Project description:Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease that ranges from simple steatosis, to inflammatory form non-alcoholic steatohepatitis (NASH), cirrhosis, and up to hepatocellular carcinoma. While NASH usually takes decades to develop at a rate of one stage per seven years, in the case of post-trasplant NASH (pt-NASH) develops fibrosis much more rapidly, with almost 50% of liver transplant recipients presenting stage 3 fibrosis by 5 years post-transplant. Archived fresh-frozen transplanted liver biopsy samples from four liver biopsy samples with evidence of NASH (2 recurrent and 2 de novo), two with simple steatosis (both de novo), and five with normal histology as controls had their transcriptome sequenced in two batches for deeper coverage.
Project description:Non-alcoholic fatty liver (NAFL) has the potential to progress to non-alcoholic steatohepatitis (NASH) or to promote type 2 diabetes mellitus (T2DM). However, NASH and T2DM do not always develop coordinately. We established rat models of NAFL, NASH, and NAFL + T2DM to recapitulate different phenotypes associated with NAFLD and its progression. Microarrays were used to identify hepatic gene expression changes in each of these models. The goal is to identify a predictor of different NAFLD progressions. Non-alcoholic fatty liver disease (NAFLD) is recognized as a low-grade systemic inflammatory state with both hepatic and extra-hepatic manifestations. We aimed to identify common key regulators and adaptive pathways in different NAFLD phenotypes. NAFL, NASH and NAFL+T2DM rat models were used to represent simple fatty liver, fatty liver with severe hepatic manifestations, and fatty liver with severe metabolic manifestations, respectively. We applied microarray analysis to characterize the key regulators and adaptive pathways in different NAFLD phenotypes. There are 12 samples in our study which belonged to 4 groups, and each group contains 3 different samples.
Project description:Through mass spectrometry, we quantified liver global proteomes of Simple steatosis and Non-alcoholic Steatohepatitis in a HFHC diet induced mouse model
Project description:Global gene expression patterns of 2 human steatosis and 9 human non-alcoholic steatohepatitis (NASH) together with their respective control patterns were analyzed to define the non-alcoholic fatty liver disease (NAFLD) progression molecular characteristics and to define NASH early markers from steatosis. Human liver samples of steatosis and non-alcoholic steatohepatitis were selected for RNA extraction and hybridization on Affymetrix microarrays. This dataset is part of the TransQST collection.
Project description:Non-alcoholic fatty liver disease is continuum of disorders among which non-alcoholic steatohepatitis (NASH) is particularly associated with a negative prognosis. Hepatocyte lipotoxicity is one of the main pathogenic factors of liver fibrosis and NASH. However, the molecular mechanisms regulating this process are poorly understood. Here, we integrated transcriptomic and chromatin accessibility analyses from human liver and mouse hepatocytes to identify lipotoxicity-sensitive transcription factors. We found that the transcription factors MAFK and TCF4 were activated in liver from NASH patients and by mouse hepatocyte lipotoxicity. Genetic deletion of these transcription factors protected hepatocytes against saturated fatty acid oversupply. Notably, MAFK- and TCF4-regulated gene expression linked to lipotoxicity closely correlated with transcriptional patters in fibrosis progression in NASH patients. Collectively, our findings uncovered novel molecular insights into lipotoxicityinduced NASH, revealing the relevance and therapeutic potential of MAFK and TCF4 in human disease.